Method of molding plastic structures and apparatus for use in same



May l5, 1923. 1,455,039

G. A. BONELLI v METHOD OF MOLDING PLASTIC STRUCTURES AND APPARATUS FOR USE IN SAME Filed Sent. 12 1921 lGrEOEMEdE" A. BONELLI, vOF RINGE/IAN, ARIZONA.

I METHOD OF MO'LDING PLASTIC `S'IRU'CTURES AND APPARATS FOR USEIN SAME.)

Appncanoafned september 12, 1921. semaine. 500,091.E

T 0 all fw hom t may concern:

- Be it known that I, GEORGE A. BONELLI, a citizen of the United States, residing at Kingman, in the vcounty of Mohave. and State of Arizona, have invented certain new and useful improvements in Methods of Molding Plastic Structures and Apparatus for Use in Same, of which the following is a specification', reference being hadV therein to the accompanying drawing.

My invention relates to an improved method of molding plastic structures and apparatus for use in practising said'method, and has for its object to provide a method of establishing an inner core of resilient material at a desired diameter, holding said core at said diameter' during the flowingand setting of a plastic mass around the same, and contracting said core to permit` its withdrawal from the set plastic structure. The apparatustherefor comprises ay tubular spirally wound resilient core, normally of larger or smaller diameter than that of the cavity to be molded, means for distending'or contracting that core to a diameter desired for molding, temporarily,

Drawings.

Fig. 1 is a side elevation of an apparatus embodying my invention. 1 Fig. 2 is a front elevation of the same. Fig. 3 is a plan view of the head employed in -said apparatus. Fig. 4 isa sectional view of the core with said head in place,y taken on the line 4-4 of Fig. 1. l vL Descrip to/n.

' The outer form 5 is of usual construction, and is spaced fromthe core 6 by the coiled annular spacing member 7. That core 6 is a spirally-wound sheet as illustrated, whose rear end or edge A is fastened to the rod 8 by bolts 9 or other attaching means, the other end of the rod 8 being provided with a crank 10 having the" handle 11. The rod 8 serves to expand or contract the diameter of the core 6, whose front end is secured against rotation bythe pin 12, mount-l ed through the walls of said core 6 as showny r in Fig. 2 ,and driven into the.y supporting ground to anchor it. l y

Alongl the line 4 4 the sheet forming the core 6 is wound upon itself as shown in Fig. 4, its outer thickness carrying iXed therein the locking rivets 13,'its inner thickness having apertures to. receive the inwardly projecting ends of said rivets when the core is at the desired diameter to do its work, so that said rivets will seat through saidapertures as shown in Fig. 4 and lock the core 6. The head 14 is a guide employed in adjustingv the core 6 to thendesired diameter, having fingerholes 15 to admit of its being readily installed or removed, and a recess 16 to accommodate the rod 8, andk other recessesl 17 about its periphery to accommodate the inner ends of the vrivets 13. AWhen said rivets 13 areseated in place as shown in Fig. 4 the head 14 is no longer needed, and

is withdrawn before the concrete or like plasticmaterial vis flowed and set about :the core 6. The material being flowed and set,

the crankqlO, which has been held during Y that operation by the looped link 18 (Secured to the eye'19 in the head of the 'pin' 12 as y shown in Figs. 1 and 2) is released and turned to compress the core 6 tosmaller diameter than the cavity it has formed in' the plastic structure, in which compressed condition said core is withdrawn from the y work and is in condition to be again set" at proper diameter for re-use.

The described parts may be altered in construction without departing from my inventiomwhich broadly-,consistsin the several combinations ofthe appended claims.

, n Ulaz'ans. 1. .The method of molding plasticstrucapplying power to the terminals vof said core to expand or contract the same to the desired diameter ffor. molding; in holding tures consisting in placing a spirally wound i y resilient tubular bodyV foruse as a core; in

said core' in expanded or contracted condi- Y,

tion whilelowing the plastic material about the sameg'an'd in releasing the terminals of said body for the purpose 'of collapsing saidl body and lpermitting its withdrawal from the plastic mass.

2. In an apparatus structures, in combination with an outer form and spaced 'therefrom by a coiled annular spacing member a spirally ywound inner core for moldingv plastic Whose normal diameter is smaller or-larger than that of the cavity to vbe molded; and means for expanding or contracting said core for use as a mold7 and relaxingsaid core for purposes of Withdrawal from the set plastic structure.

3. ln an apparatus for molding plastic structures, in combination with an outer form fand spaced therefrom by a coiled annular spacing member, a. spirallyv Wound inner core Whose normal diameter is smaller or larger than that of ythe cavity vto be molded; means yfor eXpanding or contracty ing said core/for use as a mold; means for holding,l said core in that expandedor contracted position; and meansffor relaxing said core for purposes of Withdrawal -from- GEORGE A. BONELLI 

